DFI 855GME-MGF and Pentium-M Dothan Desktop Performance

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Overclocking The Pentium M Dothan Core

Our expectations were that the Pentium M, with proper motherboard BIOS tweak support, would most likely have plenty of headroom left in it for overclocking. Let's looks at some quick vital signs and then we'll show you the maximum stable overclocked speed we achieved on the DFI 855GME-MGF.

Overclocking TheDFI 855GME-MGF And A 2GHz Dothan Pentium M

Serious overclockers

Stock 2.0GHz

OC'ed 2.53GHz

Cache Details

Motherboard/Chipset

Temps

Voltages

The great thing about the Pentium M processor is that out of the box, in retail form, it comes with its FSB multiplier unlocked. You can adjust the multiplier settings down but not up, but in general you're left with a lot of options for overclocking as a result. The DFI 855GME-MGF (and/or possibly the 855GME chipset it uses) seemed to have a stable FSB limit of 133MHz. Our 2.0GHz CPU has a stock multiplier of 20X with 100MHz FSB, which then is "Quad Pumped" just like the Pentium 4 interface for a 400MHz system bus. So, when we adjust the FSB up to 133MHz, the system bus is then oveclocked to 533MHz and the 2GHz Pentium M is taken up to 2.66GHz. The system would boot at this speed but Windows would fail to load. We ended up finding full system stability at 2.53GHz or a X19 multiplier and a 133MHz/533MHz FSB.

Beyond that, as you'll note in the shots above, the processor core is reporting 2MB of L2 cache and 32K of I-Cache (instruction) and D-Cache (data). Comparatively, a Pentium 4 EE has 2MB of L3 cache and only 8K I-Cache and 12K D-Cache, although it does have 512K of L2 cache ahead of its 2MB of L3 cache. The final thing to note in these screen captures are the thermals. We recorded a cool and comfortable 35.5oC at full load with a Folding@Home client running, at 2.53GHz overclocked speeds. This test was performed on an open air bench setup but regardless, when you consider a P4 Prescott core chip idles around 53oC at stock speeds and voltages with no load, the Pentium M's thermals are very impressive to say the least.